From f609709a58c8255188de8d6ddfa44c3f8b3abad4 Mon Sep 17 00:00:00 2001
From: Donald Sharp <sharpd@cumulusnetworks.com>
Date: Tue, 29 Oct 2019 20:24:10 -0400
Subject: [PATCH] lib, ospfd, zebra: Convert interface_delete to take double
 pointer

When free'ing the interface pointer, set it to NULL.

Signed-off-by: Donald Sharp <sharpd@cumulusnetworks.com>
---
 lib/if.c               | 30 ++++++++++++++++--------------
 lib/if.h               |  2 +-
 ospfd/ospf_interface.c |  3 +--
 zebra/interface.c      |  2 +-
 4 files changed, 19 insertions(+), 18 deletions(-)

diff --git a/lib/if.c b/lib/if.c
index e61bf00283..9d0f13ecbd 100644
--- a/lib/if.c
+++ b/lib/if.c
@@ -185,7 +185,7 @@ void if_destroy_via_zapi(struct interface *ifp)
 
 	if_set_index(ifp, IFINDEX_INTERNAL);
 	if (!ifp->configured)
-		if_delete(ifp);
+		if_delete(&ifp);
 }
 
 void if_up_via_zapi(struct interface *ifp)
@@ -283,27 +283,29 @@ void if_delete_retain(struct interface *ifp)
 }
 
 /* Delete and free interface structure. */
-void if_delete(struct interface *ifp)
+void if_delete(struct interface **ifp)
 {
+	struct interface *ptr = *ifp;
 	struct vrf *vrf;
 
-	vrf = vrf_lookup_by_id(ifp->vrf_id);
+	vrf = vrf_lookup_by_id(ptr->vrf_id);
 	assert(vrf);
 
-	IFNAME_RB_REMOVE(vrf, ifp);
-	if (ifp->ifindex != IFINDEX_INTERNAL)
-		IFINDEX_RB_REMOVE(vrf, ifp);
+	IFNAME_RB_REMOVE(vrf, ptr);
+	if (ptr->ifindex != IFINDEX_INTERNAL)
+		IFINDEX_RB_REMOVE(vrf, ptr);
 
-	if_delete_retain(ifp);
+	if_delete_retain(ptr);
 
-	list_delete(&ifp->connected);
-	list_delete(&ifp->nbr_connected);
+	list_delete(&ptr->connected);
+	list_delete(&ptr->nbr_connected);
 
-	if_link_params_free(ifp);
+	if_link_params_free(ptr);
 
-	XFREE(MTYPE_TMP, ifp->desc);
+	XFREE(MTYPE_TMP, ptr->desc);
 
-	XFREE(MTYPE_IF, ifp);
+	XFREE(MTYPE_IF, ptr);
+	*ifp = NULL;
 }
 
 /* Used only internally to check within VRF only */
@@ -1169,7 +1171,7 @@ void if_terminate(struct vrf *vrf)
 			ifp->node->info = NULL;
 			route_unlock_node(ifp->node);
 		}
-		if_delete(ifp);
+		if_delete(&ifp);
 	}
 }
 
@@ -1551,7 +1553,7 @@ static int lib_interface_destroy(enum nb_event event,
 		ifp = nb_running_unset_entry(dnode);
 
 		ifp->configured = false;
-		if_delete(ifp);
+		if_delete(&ifp);
 		break;
 	}
 
diff --git a/lib/if.h b/lib/if.h
index 6d966a2556..4ca2e79572 100644
--- a/lib/if.h
+++ b/lib/if.h
@@ -513,7 +513,7 @@ extern void if_delete_retain(struct interface *);
 
 /* Delete and free the interface structure: calls if_delete_retain and then
    deletes it from the interface list and frees the structure. */
-extern void if_delete(struct interface *);
+extern void if_delete(struct interface **ifp);
 
 extern int if_is_up(const struct interface *ifp);
 extern int if_is_running(const struct interface *ifp);
diff --git a/ospfd/ospf_interface.c b/ospfd/ospf_interface.c
index 1f5e0da944..5459e3b87c 100644
--- a/ospfd/ospf_interface.c
+++ b/ospfd/ospf_interface.c
@@ -902,11 +902,10 @@ struct ospf_interface *ospf_vl_new(struct ospf *ospf,
 
 static void ospf_vl_if_delete(struct ospf_vl_data *vl_data)
 {
-	struct interface *ifp = vl_data->vl_oi->ifp;
 	vl_data->vl_oi->address->u.prefix4.s_addr = 0;
 	vl_data->vl_oi->address->prefixlen = 0;
 	ospf_if_free(vl_data->vl_oi);
-	if_delete(ifp);
+	if_delete(&vl_data->vl_oi->ifp);
 	vlink_count--;
 }
 
diff --git a/zebra/interface.c b/zebra/interface.c
index 5871b8746f..eea80652e5 100644
--- a/zebra/interface.c
+++ b/zebra/interface.c
@@ -829,7 +829,7 @@ void if_delete_update(struct interface *ifp)
 		if (IS_ZEBRA_DEBUG_KERNEL)
 			zlog_debug("interface %s is being deleted from the system",
 				   ifp->name);
-		if_delete(ifp);
+		if_delete(&ifp);
 	}
 }
 
-- 
2.39.5